Transforming Analytics from Qualitative to Quantitative
Almost a year ago now, I wrote a post on the topic of Harvey Balls and how they can be used as a qualitative analysis tool. I have seen them used primarily in Consumer Reports and also in many marketing departments. Shown below is an example of the five scale Harvey Ball font that can be used in analysis.
The problem with this font is that it is not included in the default Excel package. In my original post, I included a link to a site that provided this font, which can be added to the default Excel fonts. Adding a new font isn’t that hard, but it does take an effort. The downside of this font is that it is a derivative of pie charts, which have shown to be ineffective in data visualization.
Chandoo at Pointy Haired Dilbert just wrote a post describing how to use Wingdings2 to accomplish the same type of visual. Also, he included a formula to automate the process when you have a table of data that you want to visualize.
So a table like this can easily become…
this Spot Matrix chart:
Using the Wingdings2 font:
Check out Chandoo’s post to see the formula to automate this process.
I think there are some limitations to this type of data visualization because it can be hard to identify/quantify the variance between two coordinates in the table. For example, can you tell the difference between Option 2 – Availability and Scalability or option 2 and option 4 Availability using the spot matrix chart above? It’s very difficult. I think the use of a table with conditional formatting can be a more effective tool for analysis. A table wouldn’t pass the pretty chart test, but would be more effective.
Suggested Reading:
The Visual Display of Quantitative Information, 2nd edition
October 9th, 2008 at 1:35 pm
Simon, you have raised a good point.
Each visualization / chart has a purpose. It would be a good idea to first identify what you need to tell and then decide which chart / tool to use. The spot matrix charts are good way to tell a story in 10-15 seconds (the story that option A is better than option B while Option C is worse of all, for eg.) and most possibly suitable in a slideshow presentation. But when you plan to use the same in a report it may fail.
Despite all my love for charts, I firmly believe that “there are no good or bad charts, only good or bad stories”.
But I agree that the circles 1 & 2 are too close in thickness that it may be difficult to tell apart 1 from 2. But again, it is a limitation of the font I have used.
October 9th, 2008 at 2:02 pm
I meant Tony…
October 9th, 2008 at 4:37 pm
@Chandoo – Thank you for the comment!
My opinion my differ a bit because I believe there are effective and ineffective charts using the same data set. I think we can both agree that once you have the visualization, the story and the analysis of the visualization is the difference maker. I would agree that a table would not have the same impact in a PowerPoint presentation like the Spot Matrix would.